Conventional polycarbonate resins are excellent in heat resistance and impact resistance, but are slightly insufficient in weather resistance. That is, they easily suffer from deterioration, such as a reduction in molecular weight or yellowing, when exposed to ultraviolet radiation. For this reason, a composition comprising a polycarbonate resin and a small amount of a ultraviolet absorber compounded thereto has been used.
However, in this case it has been difficult to maintain the amount of the ultraviolet absorber added at a constant value because the ultraviolet absorber added is lost through volatilization during extrusion or injection molding. In addition, the ultraviolet absorber added tends to cause contamination of a mold or deterioration of the working environment due to its volatility.